ref #11 Keep the order of tabs on showing diff

Author: ryu1kn

lib/commands/compare-visible-editors.js

@@ -17,11 +17,14 @@ class CompareVisibleEditorsCommand {
         this._messageBar.showInfo('Please first open 2 documents to compare.')
         return
       }
-      const textInfo1 = this._selectionInfoBuilder.extract(editors[0])
-      this._selectionInfoRegistry.set(TextKey.VISIBLE_EDITOR1, textInfo1)
 
-      const textInfo2 = this._selectionInfoBuilder.extract(editors[1])
-      this._selectionInfoRegistry.set(TextKey.VISIBLE_EDITOR2, textInfo2)
+      const textInfos = editors.map(editor =>
+        this._selectionInfoBuilder.extract(editor)
+      )
+      this._registerTextInfo(
+        textInfos,
+        editors[0].viewColumn > editors[1].viewColumn
+      )
 
       await 'HACK' // HACK: Avoid "TextEditor has been disposed" error
       await this._diffPresenter.takeDiff(
@@ -33,6 +36,13 @@ class CompareVisibleEditorsCommand {
     }
   }
 
+  _registerTextInfo (textInfos, isReverseOrder) {
+    const textInfo1 = textInfos[isReverseOrder ? 1 : 0]
+    const textInfo2 = textInfos[isReverseOrder ? 0 : 1]
+    this._selectionInfoRegistry.set(TextKey.VISIBLE_EDITOR1, textInfo1)
+    this._selectionInfoRegistry.set(TextKey.VISIBLE_EDITOR2, textInfo2)
+  }
+
   _handleError (e) {
     this._logger.error(e.stack)
   }

test/lib/commands/compare-visible-editors.test.js

@@ -2,26 +2,39 @@ const CompareVisibleEditorsCommand = require('../../../lib/commands/compare-visi
 const td = require('testdouble')
 
 suite('CompareVisibleEditorsCommand', () => {
+  const editor1 = { viewColumn: 1 }
+  const editor2 = { viewColumn: 2 }
+
   test('it compares 2 visible editors', async () => {
-    const {command, deps} = createCommand(['EDITOR_1', 'EDITOR_2'])
+    const { command, deps } = createCommand([editor1, editor2])
     await command.execute()
 
     td.verify(deps.selectionInfoRegistry.set('visible1', 'TEXT_INFO1'))
     td.verify(deps.selectionInfoRegistry.set('visible2', 'TEXT_INFO2'))
     td.verify(deps.diffPresenter.takeDiff('visible1', 'visible2'))
   })
 
+  test('it keeps the visual order of the editors when presents a diff', async () => {
+    const { command, deps } = createCommand([editor2, editor1])
+    await command.execute()
+
+    td.verify(deps.selectionInfoRegistry.set('visible1', 'TEXT_INFO1'))
+    td.verify(deps.selectionInfoRegistry.set('visible2', 'TEXT_INFO2'))
+  })
+
   test('it tells you that it needs 2 visible editors', async () => {
-    const {command, deps} = createCommand(['EDITOR_1'])
+    const { command, deps } = createCommand([editor1])
     await command.execute()
 
-    td.verify(deps.messageBar.showInfo('Please first open 2 documents to compare.'))
+    td.verify(
+      deps.messageBar.showInfo('Please first open 2 documents to compare.')
+    )
   })
 
   function createCommand (visibleTextEditors) {
     const selectionInfoBuilder = td.object(['extract'])
-    td.when(selectionInfoBuilder.extract('EDITOR_1')).thenReturn('TEXT_INFO1')
-    td.when(selectionInfoBuilder.extract('EDITOR_2')).thenReturn('TEXT_INFO2')
+    td.when(selectionInfoBuilder.extract(editor1)).thenReturn('TEXT_INFO1')
+    td.when(selectionInfoBuilder.extract(editor2)).thenReturn('TEXT_INFO2')
 
     const dependencies = {
       editorWindow: { visibleTextEditors },
@@ -31,6 +44,6 @@ suite('CompareVisibleEditorsCommand', () => {
       selectionInfoRegistry: td.object(['set'])
     }
     const command = new CompareVisibleEditorsCommand(dependencies)
-    return {command, deps: dependencies}
+    return { command, deps: dependencies }
   }
 })